The ice mountains of the Karakoram are among the world's greatest natural treasures. At 8611 metres (28,251 ft), K2 is the second tallest mountain on Earth. There are three other mountains in the range that top 8000 metres (26,247 ft) - Gasherbrum I, Broad Peak and Gasherbrum II - and more than 60 peaks above 7000 metres (22,966 ft). Extending in a south-easterly direction from the north-eastern tip of Afghanistan and spanning the borders of Pakistan,...